Just be convincing with a story about being wealthy, many ATBs will be hooked.
From what I've read, that ATB seemed to be an insecure person. Made a scene at her ex-bf's place, took one month to 'decide' before agreeing to be the murderer's boyfriend, demanding he leave his wife after finding out he was married and deliberately trying to get pregnant by him on more than one occasion.
Not a very stable individual.